Variable-pitch propeller



1,554,278 S. HEATH VARIABLE FITCH PROPELLER original Filed Feb. s, 1920 `2 Sheets-sheet 1 sept. zz,` 1925.A

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Sept. 22, 1925.

S. HEATH VARIABLE PITCH PROPELLER Original FiledFeb. 5, 1920 2 Sheets-Sheet 2 control mechanism.

Patented Sept. 22, 1925.

UNITED STATES sPENcEn HEATH, or BALTIMORE, MARYLAND.

vARIAisLE-rrrcn PROPELLER.

Application led February 3, 1920, Serial No. 356,040. Renewed February 25, 1925.

To all 'whom t may concern.'

Be it known that I, SPENCER HEATH, a citizen of the United States, residing at Baltimore, in the county of Baltimore and State of Maryland, have invented certain new and useful Im rovements in Variable- Pitch Propellers, o which the following is a specification.

This invention relates to screw propellers, and more particularly to aircraft propel- 1ers of that typev in which the blades are capable of simultaneous adjustment about their several longitudinal axes in such a manner that the pitch of the blades can be varied at will ortheir action entirely reversed. to any desired degree, all during continuous operation of the propeller.

The present invention is of a similar nature gto that covered by my prior copending application Serial No. 308,112, `filed July 2`, 1919, and its objects vare generally the same. Among the features which it comprises, in common with such prior invention are, that the blades are adjusted byy engine power delivered to the propeller, manual or bodily force being required only for conconnecting and disconnecting the operating power; and that there are no operative connections, such as clutch collars, running bearings, or the like, normally in en agement, such connectionsy being established,

lanti-friction thrust bearing, the ferrule 1s cutaway as indicated at 6, 'so as to only momentarily during changes in adjustment of the blades.

Among the specific objects of the present invention, as distinguished from my said prior application, are to eliminate the use of sprocket chains, to provide a better bearing for each propeller blade, to` improve the construction of the worm gearing employed, and to devise a novel and more effective With the above and ther objects in view the invention consists in the construction, arrangement and combination of parts' hereinafter described and claimed, and shown in the accompanying drawings, in which Fig. 1 is an end elevation, half in section showing m improved propeller hub, with the blade s anks therein;

Fig. 2 issa similar view half in section and half in side elevation;

Fig. 3 is a section on the line X-X of Fi 1, lookingtowards the right; t

Fig. 1 is a section on the line X--X of Fig. 1, looking towards the left;

Fig. 5 is a fragmentary plan view of my controlling mechanism and associated parts;

Fig. 6 is a sectional elevation thereof,'the y section being taken substantially on the line 6--6 of Fig. 5, and

Fig- 7 is a sectional elevation, substantially on the line 7*-7 of Fig. 5. Referring to the drawings in detail, 1 designates inl general my improved propeller i cured in a ferrule 6 by means of an annular wedge 7. This vferrule is rotatably held within the hub socket and is secured in position by means of a flange ring 8, between which.: and the ferrule 6 1s placed a thrust bearing 9 preferably of the anti-friction type. The inner end of the ferrule is formed with outwardly Haring walls which fit snugly within the hub socket, as indicated at 6b, thus forming abearing affording lateral support, and between this bearing and the provide a clearance between itself and the walls of the socket. This arrangement gives rise to a structure which has great stability and at the same time freedom of movement.

Securedwithin the inner end of the ferrule 6 is an internal annular gear 10, and with this gear are arranged to mesh a pair of pinions 11 positioned as shown in Fig. 3. Each pinion is rigidly mounted on a shaft 12, journaled in suitablev bearings in a frame 13 secured in the hub socket asby means of screws 14.

Also mounted on the shafts 12 are a pair of worm wheels 15 as clearly shown in Fig. 4, and these worm wheels mesh with worms 16 formed on a transverse shaft 17 journaled as at 18 in the frame 13 and carrying at its outer end a gear wheel 19. 1t will be observed that the two worms 16 are of reverse pitch and that the worm wheels 15 are dis. posed on opposite sides of the shaft 17. The result of -this construction is that when the shaft 17 is rotated the worm wheels 15 and pinions 11 are both drivenin such a direction as to co-operate in turning the annular gear 10, and with it the blade shank about its aXis.

The gear 19 meshes with a gear 2O rigidly I secured to a large gear wheel 21 journaled on a stud shaft 21'@L secured to the hub socket.

Freely journaled on an extension 4 of the hub is a sleeve 24 carrying a gear 23, and freely journaled on this sleeve is a second sleeve 30 carrying a gear 22. The gear -22 is in constant mesh with the gear wheel 21, and an idler pinion 25 journaledon a bracket 26 engages the gear 23 and, gear wheel 21, thereby constantly connecting the same.

From the above it will be understood that there is a gear wheel 21 and associated parts for each blade of the propeller, and that all of these gear wheels 21, as well as pinions 25 mesh with the two gears 22 and 23 as described.

r Secured to the sleeve 24 is a brake wheel 27 and secured to the sleeve 30 is a brake wheel 29, these wheels being held in assembled relation by a ring 28and separated by a spacing ring 28a. 31 designates the casing or frame of the engine, which drives the propeller. Secured to this frame by means of brackets 32 is a circularv housing 33 concentric with and enclosing the brake wheels 27 and 29. This housing preferably has an annular iiangev 34 positioned between the bra-ke wheels and an annular flange 35 in front of brake wheel 29.

Rigidly carried by housing 33 is an upstanding bifurcated bracket 36 between the legs of which rests a controlling lever 37. This lever is not pivoted tothe bracket '36, but can slide freely relative thereto. The inner end of this lever 37 is somewhat T-shaped, having a transversely extending portion 38 as clearly shown in Fig. 6, and in the ends thereof are set a pair of pivot pins at 42. A similar band 43 surrounds the brake Wheel 27 Land has its free end `secured to the pivot pin 39. i

Secured .to the bracket 36 is a pair of guide plates 44, 4 5, provided with curved slots 46, 47, through which the pivot pins 39 and 40 extend and in which they can freely slide. The slots in which the pin 39 worksare formed around the pin 40 as a center and 'the slots in which the pin 40 works are formed around the pin* 39 as a center. Thus the lever 37 is capable of pivotalmovement about either of the pins 39 or 40. When moved about the pin 39, it is obvious that theband 41 will be tightened, and when swung about the pin 40, the band 43 will be This arrangement produces a very eective braking action and obviates all binding or clamping of the parts.

The operation of the mechanism according to the present invention, is the sameas that of my above mentioned prior application. The tightening of the brake bands on the brake wheel 27 causes the gear wheels 21 to be driven by means of the gear 23 and the .pinions 25, thus actuating the shafts 17 and turning' the blades in one direction, while tightening of the brake bands on the brake wheel 29 causes the gear wheels 21 to be driven directly by means of gear 22, thus turning the blades in the opposite direction. In the present invention, however, I have eliminated the use of chain and sprocket gearing and have provided a transmission consisting entirely of supporting gears constantly in'mesh. This produces a construction which will stand up better at high speeds, is more compact and less liable to derangement.

While in my former application, I have shown a single worm with crossed threads, I achievethe same result in the present invention by means of two separate worms, arranged as shown in Fig. 4 and this latter construction I regard as mechanically preferable.

What I claim is: 1. A propeller comprising a 'hub having a socket. a blade having a shank rotatable about its owm aXis in said socket, and means for so rotating said blade in either direction, said means comprising a pair of independent toothed gears rotatable about the same axis, a gear wheel carried by said hub and meshing with one of said gears, "an idler pinion i .tively connecting said shaft and said last :named .gear wheel whereby rotation of the 39 and '40. A brake band 41 surrounds the brake wheel 29 and is secured at its free end` to the pivot pin 40, the other end of such-'fA .f band being fixed to the housing as indicated latter will cause rotation of the shaft, and means: mountedl within saidhub and operated. from said shaft for rotating said blade.

2. A propeller comprising a hub having a socket, 'a blade having a shank rotatable about its own axis in said. socket, and means for so rotating saidV blade shank in either direction, said means comprising a pair of independent toothed gears journaled on said hub, co-aXially thereof, and a pair of rigidly united gear wheels also rotatably supported on said hub, eccentrically thereof, one of said rigidly united Wheels being operatively connected with' said blade shank, the other of said Wheels being in mesh with one of said toothed gears, and an idler pinion.

" socket, a blade secured in said ferrule, a

' duced external diameter between said two bearings so as to afford a clearance between itself and the socket. an annular gear -secured to the inner wall of said flared portion of said ferrule, and means forrotating said gear and ferrule.

4- `In a propeller, the combination with a hub, of a bladev mounted ltherein for rotation on its own axis, and gearing for rotating said blade, said gearing including a pair of separate rigidly connected worms, mounted on the same axis, a pair of oppositely disposed Worm wheels meshing therewith, and rmeans operated by said worm Wheels for applying a turning force to said blade at points on opposite 'sides of its axis of rotation.

5. In a propeller, the combination with a hub, of a blade mounted therein for rotation on its own axis, and gearing for rotating said blade, said gearing comprising a pair of separate, reversely arranged worms mounted on the same shaft, a pair of worm Wheels meshing therewith, and disposed on opposite sides of such sha-ft, and means operated by said worm wheels for applying a turning force to said blade at a plurality of points.

6. A propeller comprising a hub having two oppositely directed sockets, a blade mounted in each of said sockets for rotation about its own axis, and means for simultaneously rotating said blades, said means comprising a pair of independent toothed gears rotatable about the; same axls, twov gear wheels carried by said hub and arranged on opposite sides of said toothed gears,` both of said gear wheels.being in mesh with one of said gears, each of said gear wheels having an idler pinion meshing therewith and with the other of said gears, each of said gear wheels also having a second gear wheel rigid therewith, two shafts extending transversely of said hub, one for eachblade, gear mechanism operatively connectingveach of said shafts with one of said second named gear wheels, whereby said shafts are rotated by rotation of said gear wheels, and means operated by rotation of each shaft for rotating its respective blade.I

7. A propeller comprising a hub having a socket, a blade having a shank rotatable about its own axis in said socket, and means for so rotating said blade in either direction, said means comprising a pair of independent toothed gears rotatable about the same axis, a gear wheel carried by said hub and meshing with one of said gears, an idler pinion meshing with said -gear wheel Arespective blade.

and with the other of said gears, a second gear wheel .rigid with said first named gear wheel, a shaft extending transversely of said hub, said shaft having on one end a gear wheel meshing with said second gear wheel, whereby said shaft is rotated, and means mounted within said hub and operated from said shaft for rotating said blade.

8. A propeller comprising a hub having two oppositely directed sockets, a blade mounted in each of said sockets for rotation about its own axis, and means for simultaneously rotating said blades, said means comprising a pair of independent toothed gears rotatable about the same axis,

ktwo gear wheels carried by said hub and arranged on opposite sides of said toothed gears, both of said gear wheels being in mesh with the one ofsaid gears, each of said gear wheels having an idler pinion meshing therewith and with the other of said gears, each of said gear wheels also having a second gear, wheel rigid therewith, two` shafts extending transversely of said hub, one for each blade, each of said shafts carryinga gear wheel which meshes with one of said second gear wheels, whereby said shafts are rotated, and meansoperated by rotation ofeach shaft for rotating its 9.l A propeller comprising a hub having a socket, a blade having a shank rotatable about its own axis in said socket, and means for so rotating said blade, said means comprising a pair of independent toothed gears rotatable about the same axis, a gear wheel carried by said hub and meshing with one.4

ofgsaid gears, an idler pinion meshing with `Said gear wheel and with the other of said gears, a second gear wheel rigid with s aid first named gear wheel, a shaft extending diametrically through said hub and transversely of the axis of said blade, said shaft having a gear wheelY meshing with said second gear wheel, and gear mechanism arranged within said hub and operated by rotation of said shaft for rotating said blade.

l0. In a propeller, the combination with a hub, of a blade mounted therein for rotation on its own axis, and gearing for rotating said blade, said gearing comprising a gear secured to said blade, pinions engaging said gearon the opposite sides of the axis of rotation of the blade, a. worm shaft extending transversely of said hub, a pair of separate spaced worms rigid with said shaft, a pair of worm wheelsdisposed on opposite sides of said shaft and engaging said worms,

each ofsaid worm wheels being connectedv 11. A propeller comprising a hub having a socket, a blade having a shank rotatable about its own axis in said socket, and fneans for so rotating said blade shank in either direction, said means comprising a pair of independent toothed gears journaled on said hub, a gear Wheel meshing with one ofsaid gears, an idler pinion meshing With said gear Wheel and the other of said gears, a Worm shaft extending diametrically through said hub and operatively connected to said gear Wheel, and means operated by said Worm shaft for rotating said blade.

12. A propeller comprising a hub having a socket, a blade having a shank rotatable about its own axis in said socket, and means for so rotating said blade shank in either direction, said means comprising a pair of gears, an` idler pinion meshing with said.,

gear Wheel and the other of said gears, a Worm shaft extending diametrically through said hubaand operatively connected to said gear Wheel, a pair of Worms spaced apart on said shaft and rigidly secured thereto, a pair of oppositely disposed worm Wheels meshing therewith, and means operated by said Worm Wheels for rotating said blade.

In testimony whereof I aHX my signature.

j sPENoEE HEATH, 

